The work being done is prep for the bigger Canarsie Tunnel project starting next April. In addition to extensive track and signal work, the weekend work will focus on preparing the tunnel and project entry sites, as well as the infrastructure above and around the tunnel among other things.

"Our crews are working hard on track and signal infrastructure during periods of lower ridership so that while the L-train tunnel is reconstructed and we run in Brooklyn only next year, it's the most reliable service we can deliver on the line," said NYC Transit President Andy Byford

The Canarsie Tunnel was one of nine underwater tunnels that flooded during Superstorm Sandy in 2012, causing extensive damage to tracks, signals, switches, power cables, signal cables, communication cables, lighting, cable ducts and bench walls throughout a 7,100-foot-long flooded section of both tubes. Bench walls throughout those sections must be rehabilitated to protect the structural integrity of the tubes.